Demo WebService isn't responding - Newbie Question

KI performance

i am unable to configure my WCF WebService and RadTreeView Control to work together 'On Demand', and because i am absolutly new with WebServices, i have no clue what is the problem. Anybody can give me a hint? By the way, i strongly use the following Demo of Telerik: http://www.telerik.com/help/aspnet-ajax/treeview-load-on-demand-wcf.html and http://demos.telerik.com/aspnet-ajax/treeview/examples/programming/performance/defaultcs.aspx

With this modified edition, i see that the WebService is called and it jumpes into the correct function. Btw. i dont know why but the webservice is called three times and the page returns 401 as error, but this is another story :)

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